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@jdh30
jdh30 / PredatorPrey.tq
Created Nov 21, 2022
Simulating predator-prey dynamics
View PredatorPrey.tq
let g = 0.02 and k = 500 and t = 1500
let evolve(r, f) =
let dtrf = 0.0001 * r * f in
Some((r, f), (r + (1.0 - r/k)*r*g - dtrf, dtrf + (1.0 - g)*f))
let () =
Seq.unfold evolve (50, 10)
@ Seq.truncate 1500
@ Array.ofSeq
@jdh30
jdh30 / KMP.tq
Last active Nov 21, 2022
Knuth-Morris-Pratt string search algorithm
View KMP.tq
let search p =
let m = # p in
let next = Array.init m [_ -> 0] in
let rec init(i, j) =
if i >= m-1 then () else
if Array.get p i = Array.get p j then
let () = Array.Unsafe.set next (i+1) (j+1) in
init(i+1, j+1)
else
if j=0 then init(i+1, j) else init(i, Array.get next j) in
@jdh30
jdh30 / Base64.tq
Created Nov 21, 2022
Base64 encoder
View Base64.tq
type State =
| S0
| S1 Number
| S2 Number
let charOfNumber n =
if n<26 then Char.ofNumber(n+65)
else if n<52 then Char.ofNumber(n-26+97)
else if n<62 then Char.ofNumber(n-52+48)
else if n=62 then '+' else '/'
@jdh30
jdh30 / SuffixArray.tq
Created Nov 21, 2022
Compute the suffix array of an array
View SuffixArray.tq
let suffixArray str =
let g = Array.get in
let n = # str in
let sa = Array.init n id in
let pos = Array.copy str in
let tmp = Array.init n [_ -> 0] in
let sufCmp gap (i, j) =
compare (g pos i, g pos j) @
[ Equal ->
if i+gap >= n || j+gap >= n then compare(j, i) else
@jdh30
jdh30 / MaxSumSubseq.tq
Created Nov 21, 2022
Maximum sum subsequence
View MaxSumSubseq.tq
let maxSumSubseq a =
let maxm = Array.fold [a, b -> max a b] 0 a in
let rec loop sum i =
if i = # a then sum else
let ai = Array.get a i in
if ai > 0 then loop (sum + ai) (i+1) else loop sum (i+1) in
loop 0 0
View PythagorasTree.tq
let branches m =
{ { Vec2.rotate(π/2 - asin(4/5));
Vec2.scale(4/5, 4/5);
Vec2.translate(0, -1) };
{ Vec2.translate(1, -1);
Vec2.rotate(-π/2 + asin(3/5));
Vec2.scale(3/5, 3/5);
Vec2.translate(1/3, 0) } }
@ Array.map [m2 → Array.concat{m; m2}]
@jdh30
jdh30 / InfinitePowerSeries.tq
Created Nov 21, 2022
Infinite power series
View InfinitePowerSeries.tq
let toHtml f =
let x = Html "&#119909;" in
let pow = (* xⁿ *)
[ 0 → {Html "1"}
| 1 → {x}
| n → {x; Html.tag "sup" {"style", "font-size:70%"} (Html.ofNumber n)} ] in
let append(xs, x) = Array.Unsafe.append xs x in
let appends(xs, xss) = Array.fold append xs xss in
let minus = Html.of " - " in
let ellipses = Html " + &#8230;" in
@jdh30
jdh30 / NQueens.tq
Created Nov 21, 2022
Find solutions to the n-queens problem
View NQueens.tq
let safe (x1, y1) (x2, y2) =
x1 <> x2 && y1 <> y2 && x2 - x1 <> y2 - y1 && x1 - y2 <> x2 - y1
let rec next n s =
Stack.pop s @
[ None -> None
| Some((qs, ps), s) ->
Stack.pop ps @
[ None -> if Stack.length qs = n then Some(qs, s) else next n s
| Some(q, ps) ->
@jdh30
jdh30 / CorrelationCoefficient.tq
Created Nov 21, 2022
Computes the Pearson's rank correlation coefficient
View CorrelationCoefficient.tq
let pearsonsCorrelationCoefficient xys =
let n = Array.length xys in
let ∑xy, ∑x, ∑y, ∑x2, ∑y2 =
Array.fold [(∑xy, ∑x, ∑y, ∑x2, ∑y2), (x, y) →
∑xy+x*y, ∑x+x, ∑y+y, ∑x2+x*x, ∑y2+y*y]
(0, 0, 0, 0, 0) xys in
(n*∑xy-∑x*∑y)/(√(n*∑x2-∑x*∑x)*√(n*∑y2-∑y*∑y))
@jdh30
jdh30 / Primes.tq
Created Nov 21, 2022
Generate prime numbers using an online Sieve of Eratosthenes
View Primes.tq
let primes =
let a = {2} in
let grow() =
let p0 = Array.get a (Array.length a - 1) + 1 in
let b = Array.init p0 [_ → True] in
let () =
Array.fold [(), di →
let rec loop i =
if i >= Array.length b then () else
let () = Array.Unsafe.set b i False in